Perhaps you should try some spelling variations:
"research problems" » "research process", "research project", "research program"
"research progress" » "research program", "research project"
"research projects" » "research project"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("research problems") OR ("research progress"))) OR ("research projects")).
• Removing quotes may allow a broader search: (((( research problems ) or ( research progress ))) or ( research projects )).
• Adding a wildcard symbol may retrieve word variants: (((("research problems") or ("research progress"))) or ("research projects"))*.